Preparation and breakdown strength of TiO2 fluids based on transformer oil

Transmission and distribution transformers are a critical part of the electricity generation and distribution network. The potential consequence of transformer failure can cause operation disruption and financial losses. In recent years, magnetic nanoparticles have been used to enhance the dielectric breakdown strength of transformer oil. Considering the inherent magnetic property of the magnetite nanoparticles, their distribution and stability in the fluid under magnetic field is still a challenge. In this paper, a new class of colloidal dielectric fluids was explored by dispersing TiO₂ nanoparticles into transformer oil through ultrasonic treating. Breakdown voltage measurements under AC stresses were carried out for a number of different colloidal systems with varying nanoparticle content and surface modification. The observed results indicated that the addition of TiO₂ nanoparticles to transformer oil can enhance its dielectric strength and the surface compositions of the TiO₂ nanoparticles play an important role in its dielectric performance. The effect of nanoparticles´ surface modification on the breakdown strength of colloidal systems has been investigated.